Why do Pugs have short snouts?

Why do Pugs have short snouts?
Pugs have short snouts due to a genetic trait known as brachycephaly. Brachycephalic dogs such as Pugs have flattened and shortened facial features, including a short snout and a pushed-in appearance.
The short snout of Pugs is a characteristic that has been intentionally bred for generations. While it gives Pugs their distinctive look, it’s important to note that brachycephalic breeds, including Pugs, can face certain health issues associated with their facial structure.